Brush holder for dynamo-electric machines



Jan. 6. 1925. 1,521,605

7 F. DIEHL BRUSH HOLDER FOR DYNAMO ELECTRIC MACHINES Filed Dec. 12, 1925I Egfl2 f INIVENTOR I M v B AT To Patented Jan. 6, 1925.

UNITED STATES 1,521,605 PAEN OFFICE.

FREDERICK DIEHL, F ELIZABETH, NEW JERSEY, ASSIGNOR TO DIEHL MANUFAC-TURING COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEW JERSEY.

BRUSH HOLDER FOR DYNAMIC-ELECTRIC MACHINES.

Application filed December 12, 1923. 'Serial No. 680,090.

To all whom it may concern:

Be it known that I, FREDERICK DIEHL, a citizen of the United States,residing at Elizabeth, in the county of Union and State of New Jersey,have invented certain new and useful Improvements in Brush Holders forDynamo-Electric Machines, of which the following is a specification,reference being had therein to the accompanying drawings.

This invention relates to dynamo-electric machines and has for an objectto simplify and improve the brush-holder and yoke construction of suchmachines and reduce the number of parts while retaining eflicientinsulation and ease of adjustment of the electrical angle of thebrushes.

Another object of the invention is to provide a metallic yoke havingmetallic brush-holding ,means mounted thereon in efficiently insulatedrelation without recourse to the usual bolts, screws, insulating wash.-ers, bushings and the like which are liable to work loose and permit thebrush-holder to sag;

According to the present improvement the metallic brush-holders arepermanently secured in insulated relation to a metallic yoke by amolding operation involving the use of a phenol resin, such as bakelite,which hardens under heat and pressure applied during the moldingoperation and will not thereafter soften under the heat of operatingconditions. The brush-holder and yoke are formed with bonding surfacesor irregularities into intimate engagement with which the mass of moldedinsulation flows under pressure and subsequently hardens, therebypermanently and securely gripping the brush-holder and yoke in insulatedrelation to one another. The yoke may take the form of a simplesheet-metal ring having bonding surfaces provided in the form of strucklip-tongues and counter-sunk apertures, while the brush-holders maycomprise simple metallic tubes of rectangular cross-section, the sidewalls of which sunk apertures and surrounds the tongues,

effectively insulating the brush-holder from the yoke-ring, affording a"construction of great simplicity, 'mechan'ical strength, du

rability and freedom from trouble in operation, and one which can bemanufactured in large quantities at low cost. The present brush-holdermay be mounted directly in contact with the inner wall of the metallicend-cap of the motor or generator frame; provision for adjustment of thebrushes being afforded by arcuate slots in the yoke ring of thebrush-holder which slots are entered by screws passing through the wallof the end-cap and threaded into nuts having tongues extending into saidslots to prevent their turning with the screws.

In the accompanying drawings, Fig. l is a longitudinal vertical sectionthrough the frame of an electric motor embodying the invention. Fig. 2is a section on the line 22, Fig. 1. Fig. 3 is a longitudinal horizontalsection through the motor frame showing the brush-holder and yokeconstruction in plan. Fig. 4 is a sectional view in larger scale on theline H, Fig. 2. Fig. 5 is a sectional view on the line 55, Fig.2. Fig. 6is a perspective view of the yoke ring. Fig. 7 is a perspective view ofone of the brush-tubes, and Fig. 8 is a perspective View of one of thescrew-nuts into which the holding screws for the yoke are threaded.

In the preferred embodiment of the invention, as illustrated, 1represents the brush-holder yoke in the form of a sheetmetal ring.having bonding surfaces provided, for example, by the struck up tongues2, 2, and back countersunk apertures 3; said ring also having theconcentric arcuate slots 4 to provide for angular adjustment ofthebrushes. Associated with the yoke-ring l are the diametricallyopposed and alined brush-tubes 5 of rectangular cross-section, the sidewalls of which are externally grooved longitudinally at 6 and the bottomwall of which is transversely grooved at 7 to provide bonding surfaces.The tongues 2 are disposed in pairs with the tongues of each pairoppositely directed and inclined at an angle of say to the plane of thering 1; a back countersunk aperture 3 being of heat-resisting insulationmaterial, such as bakelite, which is molded into intimate engagementwith and firmly grips the walls of the bonding surfaces provided on thebrush-tubes and yoke-ring, thereby permanently joining the brush-tubesto the ring-yoke. It will be noted that the masses 8 of insulationmaterial are disposed entirely at one side of the plane of that face ofthe yoke-ring which is more remote from the brush-tubes, whereby suchyoke-ring face remains flat'and devoid of projections and may be securedflatwise to. the internal [lat wall 9 of the end cap 10 of themotorframe.

The closed end wall of the end cap 10 is formed adjacent the armaturebearing boss 11 with apertures 12 for the screws 18 which are passedthrough the arcuate slots l in the yoke-ring and threaded into the nuts14 which latter are formed with projections 15 entering the slots 4: andserving to prevent such nuts from turning. By virtue of thisconstruction the screws 13 which are accessible exteriorly of the motormay be readily loosened to permit adjustment of the electrical angle ofthe brushes and tightened after such adjustment has been made.

Having thus set forth the nature of the invention, what I claim hereinis 1. Brush-holding means for dynamo-electric machines comprisingmetallic yoke and brush-holding elements having bonding surfaces andheat-resisting insulating material molded into intimate engagement withsuch surfaces and permanently holding said elements in insulatedrelation.

.2. Brush-holding means for dynamo-electric machines comprising ametallic yoke ring and a plurality of metallic bruslrtubes, said ringand tubes having bonding surfaces,

and masses of molded heat-resisting insulating material intimatelyengaging such surfaces and permanently holding said elements ininsulated relation.

3. Brush-holding means for dynamo-electric machines comprising asheet-metal yoke ring having angularly spaced bonding apertures, a pairof alined radially disposed metallic brush-tubes spaced from said ringand having bonding surfaces adjacent the bonding apertures in said ring,and masses of molded heat-resisting insulating material filling thespaces between said ring and brush-tubes and intimately engaging saidbonding apertures.

4. Brush-holding means for dynamo-electric machines comprising asheet-metal yoke ring having angul-arly spaced bonding apertures, a pairof alined radially disposed metallic brush-tubes spaced from said ringand having bonding surfaces adjacent the bonding apertures in said ring,and masses of molded heat-resisting insulating material filling thespaces between said ring and brush-tubes and intimately engaging saidbonding apertures, said brush-tubes and the masses of molded materiallying wholly on one side of the plane of that face of said yoke ringwhich is the more remote from said brush-tubes.

A sheet-metal brush-holder yoke having one or more struck up tongues, ametallic brush-tube substantially parallel to and spaced from saidsheet-metal yoke adjacent said tongues, and formed with bondingsurfaces, and a mass of heat-resisting insulating material filling thespace between said yoke and tube and intimately engaging said tonguesand bonding surfaces.

6. A dynamo-electric machine having a frame formed with an armaturebearing and a flat internal end-wall adj acentl said bearing, asheet-metal yoke ring secured flatwise to said internal end wall andformed with bonding surfaces-entirely at one side of the plane of saidend-wall, a lurality of brushtubes disposed radially o and spaced fromsaid yoke-ring and formed with bonding surfaces, and masses of moldedheat-resisting insulating material intimately engaging said bondingsurfaces and permanently securing said brush-tubes in insulated relationto said yoke-ring.

7. A dyna-moelectric machine having a frame formed with an end wall, ascrew having its head disposed externally of and its shank passedthrough an aperture in said end wall, a sheet-metal brush-holder vokering disposed within said end wall and having an arcuate slot alsoentered by the shank of said screw, and a nut into which said screw isthreaded, said nut having a projection entering said arcuate slot.

I testimony whereof, I have signed my name to this specification.

FREDERICK DIEHL.

